In Art Spotlight, we invite Sketchfab artists to talk about one of their designs.
I live near Barcelona (Catalonia) and I studied Fine Arts and Applied Arts at the University of Barcelona. Catalonia is an area, rich with medieval porticos and cultural heritage. Just recently I published this portico near my town:
But today, we will focus on the details of the Santa Maria de Vilagrassa.
For years I taught Audiovisual Communication at the University Pompeu Fabra and I have done research on different topics but specially on color and representation patterns, as amassed in my collection, ‘Color solids’ on Sketchfab, you can see different representations of 3D classic models.
In 1985 I bought my first computer, an AMIGA 1000 with 4096 colors, a mouse and GUI. Using that setup, I taught myself the basics of digital imaging. Since 1990 I have been working professionally in graphic design, interactive project development, 3D modeling, and animation.
In 1996 I was involved along with various European artists in a pioneering project led by Roy Ascott to explore collaborative artistic creation in new media using the networks: Art-Id / Id-CYB.
Then for the last ten years, I have focused on producing television documentaries about art and documenting the cultural heritage of Catalonia.
I have been interested in Virtual Polychromy for a long while and during my studies of the subject. In my studies, I learned that most of classic sculpture/architecture (Greek and Roman) and stone works from the European Gothic and Medieval periods, were not displayed as naked stone but were actually painted. Some authors such as the architect Charles Garnier at the end of the 19th century did color representations of Greek temples discovered in archaeological excavations.
The work that has impacted me the most is the incredible project Gods in Color, by the German archaeologist Vinzenz Brinkmann and his team.
Following a rigorous scientific approach and leveraging modern technology to identify the remains of color in the classical sculpture, Vinzenz and his team created replicas of classic sculpture in plaster and painted them with real colors, displaying them as they would look 2500 years ago.
My conclusions from studying his work and many others are this:
- It is important to recover the aesthetics of polychrome sculpture and architecture of classical and medieval Art History that we have long thought to be naked stone.
- We currently have the means to represent these images digitally, creating three-dimensional models using accurate photogrammetry programs and ‘painting’ using digital techniques.
- This tools are already very accessible and a have a huge dissemination potential.
- Experts should study the archaeological remains in detail to give a scientific foundation to these representations.
For six months I have been studying medieval polychromed stoneworks. An in-depth PhD thesis on the subject by Jorge Rivas (from Complutense University, Madrid) helped me a lot, as well as general treaties like Colour and Culture by John Gage (1993).
To test my ideas, I finally decided to use one of the many Romanesque sculpture works near where I live. In the small neighboring town of Vilagrassa, there is another small 13th century church, Santa Maria de Vilagrassa, with a magnificent portico
On June 2016, I captured the model with the photogrammetry technique using a Canon 5DMkII, optical 16-35mm f / 2.8 and a 8m tripod. I took a total of 268 photos.
In the same place and time of the day, I captured a 360º image that represents the global illumination environment model in Sketchfab.
The processing of the images was done with the program Photoscan (Agisoft).
Here you can see a general model of the portico:
and then a more detailed with more resolution, featuring the friezes on top of the columns.
Virtual Polychrome Process
That was the most difficult part. A big challenge was to find any references of aesthetic painting of sculptures in the 13th century from that geographical area. Secondly, I had to find a software suitable for ‘digital painting’.
I contacted several archaeologists and historians to ask for help in the project, specially to get scientific guidance, but unfortunately I found no collaboration.
The person who actually helped me was the artist Josep Minguell, a professional mural painter specializing in the traditional technique of fresco. Minguell gave me very practical advice, specifically regarding paint pigments palettes used in Romanesque painting. It was basically a combination of five colors: black, white, ocher, red and a sort of greenish blue (Aerinite), a mineral extracted from the nearby mountains (the Pyrenees).
We had some discrepancies with regard to the practical use of gold leaf on the outside, but recent discoveries in other nearby doorways in the same period (such as in the Portico in Ripoll) persuaded me to use gold texture.
As for the software, I did different tests and research on the possibilities of ‘painting’ on a complex 3D model obtained by photogrammetry. I tried several applications like Cinema 4D / BodyPaint, Z-Brush, Substance Painter, 3D-Coat and some others. All have advantages and disadvantages, but BodyPaint and 3D-Coat allowed me to better ‘paint’ directly on a 3D model.
The process was quite slow as I had to create a layer for each color and shape, so I could then paint and modify colors at will, visualizing different scenarios.
I finally published the model in Sketchfab as a colored frieze piece which allows easy exploration of the shape and texture of a complex model like this one, impossible to exhibit properly as a series of flat images.
It would be interesting in the future to have an interactive control system allowing Sketchfab to show and hide textured layers of the same model, for example allowing users to view and compare the original texture of stone layers, and then adding layers of paint (many doorways and sculptures have been repainted over the centuries according to the aesthetics of the time), helping establish the working hypotheses.
To summarise the work process and the results I created this video where the different stages of the process are demonstrated.
With this work we have seen recreating the sculptural or architectural models and virtually hypothesizing on how the polychromy originally looked is not only possible but relatively easy to perform. Moreover, thanks to platforms like Sketchfab, these can also easily be shared. I’d love to participate in a project where experts like archaeologists or historians and others, would scientifically study a set of sculptural remains. From those results, I could create virtual accurate representations.
Thanks, Josep! What cultural heritage sites are around you? Could you apply these coloring techniques to them?